Defender scan hanging around 56%

Testing defender on a MS dev project
Scan Hangs at 57.6% (Analyzing wp-content files)
Around 55% it flashes an undefined message prior to moving to 56.7% before it hangs (let run for several hours).

Did the basics, disabling plugins etc.

Tested on another site with same basic configuration (same theme framework, child theme - same basic plugins, same hosting service) and no problems.

Access granted, just in case.